1. Field of the Invention
The invention relates in general to an image access method and an image access apparatus, and more particularly, to an image access method and an image access apparatus of three-dimensional (3D) display technologies.
2. Description of the Related Art
In the recent years, three-dimensional (3D) display technologies are developed at an overwhelming speed and are widely applied in various devices, e.g., projectors, televisions, display devices and panels of mobile devices. Referring to FIG. 1, a fundamental 3D image display architecture 100 usually includes a plurality of image sources 112 and 114, a processor 120, and a display device 130. The image sources 112 and 114 respectively represent images observed at different viewing angles. For example, in FIG. 1, the image source 112 may represent an image that is suitably viewable by the left eye, and the image source 114 may represent an image that is suitably viewable by the right eye. According to a predetermined pixel format arrangement, the 3D image display architecture 100 accesses images from the image sources 112 and 114 by the processor 120, and processes the accessed images and outputs the processed images, or directly outputs the accessed images, to the display device 130 that then displays a 3D image. However, as the display device 130 supports predetermined pixel format arrangements to thus present predetermined 3D image effects, the display device 130 can only correctly display the 3D image given that the predetermined format arrangement processed by the processor 120 and the predetermined pixel format arrangement supported by the display device 130 are consistent.
Current pixel format arrangements for 3D image display are not standardized, and so many different pixel format arrangements are available in the application of the 3D display technologies. For example, referring to FIG. 2, a pixel format arrangement may be utilizing pixels of the image sources 112 and 114 in turn in a unit of pixels, with each of the pixels including R, G and B sub-pixels. In other words, an output image 200 outputted to the display device in turn presents the pixels of the image sources 112 and 114 in a unit of pixels. Referring to an output image 300 in FIG. 3, a pixel format arrangement may also be in turn presenting the sub-pixels of the image sources 112 and 114 in a unit of sub-pixels. Referring to an output image 400 in FIG. 4, compared to the non-quincunx pixel format arrangement in FIG. 2, the pixel format arrangement in FIG. 4 is a quincunx arrangement. A main difference between a non-quincunx arrangement and a quincunx arrangement is that, the quincunx arrangement, instead of consistently utilizing a pixel of the image source 112, in turn utilizes a pixel of the image source 112 and a pixel of the image source 114 as a starting pixel of each horizontal scan line. Referring to an output image 500 in FIG. 5, compared to the pixel format arrangement in FIG. 3 in a unit of sub-pixels, the arrangement in FIG. 5, according to a presentation sequence of horizontally shifting in a unit of sub-pixels along with a vertical coordinate of a horizontal scan line, presents sub-pixels from the other image source after every other three sub-pixels (not necessarily of the same pixel). Referring to an output image 600 in FIG. 6, to prevent a dead zone in current 3D image display, many 3D image display devices employ slanted lenticular lens technologies that access data in a unit of sub-pixels from images (e.g., images sources a to g) captured from different viewing angles. As such, the pixel format arrangement may become even more complicated.
Base on the above, in order to support various pixel format arrangements, current techniques provide a solution for different pixel arrangements through different software/hardware designs. That is, an exclusive software/hardware design is provided for each of the pixel format arrangements. However, such approach not only increases design costs but also offers limited flexibilities. Therefore, there is a need for a flexible software/hardware processing architecture that coordinates with a pixel format arrangement supported by a rear-end display device to appropriately access data from multiple image sources, thereby at the same time achieving objects of compatibility as well as reduced costs and enhanced flexibilities.